TORONTO -- The debate about treating
depression with drugs, psychotherapy, or a combination of both drugs and
psychotherapy has raged on over the years. But a recent analysis of 39
studies of 3,252 depressed patients, presented at the American
Psychological Association's (APA) 104th annual convention, found that 50
percent of the drug effect is due to the placebo response. In other words,
a patient taking antidepressant medication with a self-reported
improvement rate of 10 points, can attribute half (.5) of that improvement
to the placebo effect.

To determine the placebo effect of antidepressant medications,
psychologist Guy Sapirstein, Ph.D., at the University of Connecticut,
analyzed 39 studies of depressed patients from 1974 to 1995. The studies
included patients with a primary diagnosis of depression, were randomized,
and controlled for patients who received no treatment. Studies that
measured the effects of antidepressant medications such as fluoxetine
(Prozac), sertaline (Zoloft) and paroxetine (Paxil) were included in the
analysis.

Dr. Sapirstein concluded that the pharmacologic and nonpharmacologic
effects of antidepressants indicates that while only 27 percent of the
response to medication is due to the medication alone (a true
pharmacologic effect), 50 percent is due to the psychological impact of
administering the medication (placebo effect) and 23 percent is due to
other 'nonspecific factors.' 'People benefitting from drugs are
benefitting because they think that taking the antidepressant medicine is
working,' Dr. Sapirstein said. 'If we take these results and say that
improvement is due to what the patients think, then how people think and
its effect on how they feel are more powerful than the chemical
substance,' he added.

In addition, the study found that patients who either took medication
or underwent psychotherapy exclusively had similar treatment outcomes. The
promise of future treatment, which was controlled for by the wait-listed
patients, did not affect depression levels.

The American Psychological Association (APA), in Washington,DC, is the
largest scientific and professional organization representing psychology
in the United States and is the world's largest association of
psychologists. APA's membership includes more than 132,000 researchers,
educators, clinicians, consultants and students. Through its divisions in
49 subfields of psychology and affiliations with 58 state and Canadian
provincial associations, APA works to advance psychology as a science, as
a profession and as a means of promoting human welfare.